1a. Fertile anthers 4.............................................................................................................................................................. M. nepalense
1b. Fertile anthers 2..................................................................................................................................................................................2
2a. Involucral bracts connate at the base forming a shallow cup; involucel teeth 1/2 or less as long as tube.................... M. polyphylla
2b. Involucral bracts free; involucel teeth at least 2/3 as long as tube.....................................................................................................3
3a. Leaves entire or slightly toothed; flowers usually 20 or more close-packed whorls, 8–12 flowers in each whorls........ M. ludlowii
3b. Leaves lobed; flowers few, distantly arranged in whorls...................................................................................................................4
4a. Flowers yellow; stamen filament about half as long as corolla lobe............................................................................ M. coulteriana
4b. Flowers white or pink or pinkish-white; stamen filaments longer than half of corolla lobe..............................................................5
5a. Calyx entire or emarginate; stamen filaments ca 10 mm long............................................................................................ M. persica
5b. Calyx lobes bi-fid; stamen filaments 1–3 mm long......................................................................................................... M. longifolia